Ultrasonic, electronic, and mechanical instrumentation is to be obtained to update the existing field measurement and calibra- tion facilities and to introduce a semi-automated capability to measure repeated short pulse and transient pulse ultrasound fields. The existing instruments were designed and fabricated more than 30 years ago and are now in need of updating in order to assure that accurate and reliable usage continues and that the Laboratory has the capability to deal with the types of measurements that current investigations require. The instrumentation is absolutely essential for calibrating the output of acoustic emission devices (transducers) for the exposure of animal systems involved in the study of mechanisms of interaction, immunological response, dosimetry, and for the purpose of measuring ultrasonic propagation properties of biological media. Further, the proposed updating will make available the capability of greatly expanding the scope of the work undertaken by the investigators dealing with different biomedical ultrasonic topics, by allowing for accurate measurements of short pulse exposures to be carried out, and thereby providing armamentaria to the temporal domain of clinical diagnostic ultra sound.